1. Field of the Invention
The present invention relates to structures for directing the air flow in a dynamo electric machine such as an electric motor or an alternator, and in particular to structures for directing the air flow through the stator of a dynamoelectric machine.
2. Brief Description of the Related Art
As shown in FIG. 2, the stator 10 of a typical dynamo electric machine is formed by a series of coils 12 held in a solid body 14, e.g., a series of metal plates laminated together. The coils are held in position relative to one another by a tie ring 16.
The stator 10 is cooled by air blowing past the stator 10, through any available air channels in the stator 10 and through the gap between the stator 10 and the rotor 17, as shown generally by the arrows A. Only the ends 18 of the coils are directly exposed to the air flow, and while a chamfer 19 helps direct air towards the ends 18, very little of the air actually passes through the ends 18 due to the high flow resistance through the ends. Instead, most of the air flows around the outside surface of the coil ends.